Chestnut will play trauma doctor Ike Prentiss, a former Army medic who learns about beside care from Jackie (Edie Falco).

The 43-year-old actor is known for appearing in such films as 1991's Boyz n the Hood, 1999's The Best Man and 2002's Like Mike. He recently played a recurring role in the first season of FX's American Horror Story.

Nurse Jackie has also cast Marcy Harriell in a recurring role - the Ed actress will play Marta Rodriguez, an over-worked nurse who takes on extra shifts to provide for her three children.

New showrunner Clyde Phillips recently claimed that Nurse Jackie will get a "reboot" for its fifth season, with cast changes likely.

The new run will begin filming in late 2012 for broadcast in 2013 on Showtime, while season four will air on Sky Atlantic in the UK from Tuesday, October 9 at 10.35pm.